We are trying to increase populations of the berry bee, Osmia aglaia, for pollination of cane fruit in the Pacific Northwest. Follow our progress...

Sunday, April 29, 2012

Mating orgy at the nests

Four mating couples

A male tries to mate with another male

Male orchard bees emerge first, and the females a few days later. We seem to be in the midst of female emergence today. The top photo shows four mating couples. Three of them are on top of the blue emergence box in front of the upper cottage cheese container emergence box. One couple is on top of the wood nest block. I don't have time to watch, but if someone wanted to know how long matings last, you could get quantitative data today.

The emergence containers are covered with bee meconia from the emerging bees. That's a fancy name for bee poop. The adults have been storing it in their bodies all winter, and only after they emerge in the spring do they relieve themselves. If you look around the shelter you'll see meconia on the nest blocks and the bottom shelf that holds the nests as well.

Both of the bees in the bottom photo have long antennae, and both have yellow faces (not seen in this photo), so they are both males. The bottom male didn't do much to knock the top male off. They stayed connected for more than 4 minutes with the top male trying repeatedly to mate with the bottom one.

Bosch and Kemp's manual on orchard bee management has a concise passage about what's going on today at the bee nests: "Emergence is timed so that males (located in the outermost cells) emerge one to three days before females. Once out of the nest, newly emerged adults excrete their meconium as a few drops of whitish, quickly solidifying secretion evacuated from the anus. The meconium contains metabolic waste products. Adults then engage immediately in mating activities or fly to nearby flowers to take nectar."

Raspberries leafed out, flowering tree in distance

The raspberries are not yet blooming at Sturm Berry Farm, but I'm sure there are some weeds in bloom. You can also see a large tree on a neighboring property that appears to have pink bloom. It looks like there may be a few blueberry flowers in bloom. We'll see if there is enough bloom to keep the orchard bees nesting at our bee shelter by the number of nest tunnels that are completed over the next few weeks.

Blueberry bush with buds

Buds are developing on the blueberry bushes. Some of them may be open. It will be interesting to see what visits the flowers, in particular can we see blue orchard bees visiting them. This plant is visible from the preset location "blueberry closeup 2".